Alphabet Inc. the newly founded parent company headed by CEO Larry Page to replace Google Inc. Alphabet is mostly a collection of all the companies under Google Inc. The largest of which, of course, is Google itself. Now Google will become a wholly-owned subsidiary of Alphabet.
Also the Board has announced 43'years old India-born Sundar Pichai as the CEO of Google. He served as Google's Android chief, and lead the company's charge in wearable and TV technologies.
Alphabet https://abc.xyz/ is the new website URL for the parent company and all the sub companies will come under it, shares will continue to trade on Nasdaq as GOOGL and GOOG as announced by Larry in the official blog.
The Alphabet family of companies are Android, Blogger, Chrome, Google, YouTube, etc..